Bike running lean???

Rethy · Post by **Rethy** » Sun Feb 26, 2006 7:27 pm

Noticed the exhaust right off both heads very hot (orange glow) and it was only about 42 degrees out today. Never noticed this before. One thing I did different is the idle has been too low, about 900 RPM and would die if I chop the throttle. I adjusted the cable at the throttle housing too high cause I was in a hurry about 2000RPM. I know it is too high but was not to concerned since I would be riding the back highways it would not be idling anyway. I have been using the fast idle lever to keep the idle at 1100 RPM since I got the bike in November and most riding days see temps in upper 30 to low 40 degree temps. I figured the bike was running a little cold with these ambient temps. It has been running rich with fast idle but runs good. Since I increased the idle I shut off the fast idle and now appears lean. The bike has a 2Brothers complete exhaust system and not sure if fuel system is able to adjust for less backpressure. The previous owner said I may need to remap the fuel program. He never did this after installing pipe and mentioned it was cold blooded but ran fine when he rode in warmer temps. Anyone seen this before??? Thanks for replies------Rethy

Tripton · Post by **Tripton** » Sun Feb 26, 2006 8:31 pm

I just put a Two Brothers on my Rockster, I am also in Iowa, and I ran it all over yesterday. About 26-30 degrees. Never had your problems at all, mine seems to run great with the pipe actually. Might have lost a little oomph in the low RPMs.....but if any, not much. How do you like the sound of that pipe?

Id get it checked out. Lean is bad.

Post by **Boxer** » Sun Feb 26, 2006 8:49 pm

These bikes run lean normally thus the traditional blue pipes, but orange glowing pipes is way too hot. They only do that if left idling and setting still with no air flow on the pipes.

2000 is also too high idle. It should be 1100 after warmed up. The high idle is only there to keep the idle up until she gets warm. DO NOT let it set to warm up! Flip up the high idle lever and hold it in the highest position until she starts then let it spring back to the high idle. After a few blocks reach up and flip it down. You should then be seeing 1100 rpms at idle.

To adjust idle, turn the two BBBPSs (Big Brass By Pass Screws) on each throttle body equally slightly counterclockwise.

Rethy · Post by **Rethy** » Sun Feb 26, 2006 9:16 pm

Thanks for the replies. I knew the 2000 was way high. I now have it set about 1200. I thought you need to hook up the vacuum instrament to play with the brass screws. It was probably idling for 5 minutes after my ride, time to get garage opened up and tools to loosen and adjust throttle. Maybe now that idle is lower it can operate longer while sitting still. Bike runs great was just concerned today after seeing exhaust glowing. Thanks again for replies.-------Oh and the yes I do like the exhaust note with the 2Brothers, actually the main reason I got the bike. I wanted a RT but after I heard the low but snappy rumble of this 1150R I had to ride it. Well after that the rest is history. Thanks again for the replies.----Rethy

Post by **Boxer** » Sun Feb 26, 2006 9:19 pm

I thought you need to hook up the vacuum instrament to play with the brass screws.

Technically, you do. But you can bring the idle down or go up if you move them "equally" in the same direction. Then when you have time, put the sync instrument on them and get them EXACTLY even.

fnfalman · Post by **fnfalman** » Mon Feb 27, 2006 11:23 am

These bikes already run fairly lean from the factory and with an aftermarket exhaust PLUS Y-pipe, they'd run even leaner. You should hook up a gas analyzer to the exhaust and play around with the air mixture setting. Or have a shop that has the equipment to do this for you.

Or just shell out for a Power Commander and some dyno tuning.

dilligaf · Post by **dilligaf** » Mon Feb 27, 2006 5:06 pm

These bikes already run fairly lean from the factory and with an aftermarket exhaust PLUS Y-pipe, they'd run even leaner.

Careful Fnfalman, you'll incur the rath of Dallara.
(Sorry everyone, i still have trouble letting that go)

fnfalman · Post by **fnfalman** » Mon Feb 27, 2006 6:33 pm

All I know is that my bike now has no flat spots and it revs cleanly throughout the whole power range.

Post by **socalrob** » Tue Feb 28, 2006 1:10 am

Its not that uncommon that when I shut my bike off in a dark garage at night, after a spirited ride, that I notice a dull red glow from the headers. My idle is between 11 & 1200.